1. Field of the Invention
The present invention relates to an automatic white balance control system, an automatic white balance module, and a method thereof, and more particularly to an automatic white balance control system, an automatic white balance module, and a method thereof, capable of sampling an image by dynamically adjusting threshold value and the image sharpness.
2. Description of the Related Art
At present, a digital camera generally comes with an automatic white balance function, since the color of an object varies depending on the color of a projected light, and thus the color temperature of a picture taken at a different place differs accordingly. For example, a picture taken in an illumination environment of a tungsten light bulb may appear to be slightly yellow. The automatic white balance function is provided for correcting an error caused by external lights and adjusting the intensity of three primary colors (R, G, B) in an image according to the pixel properties of the image.
Most conventional processing methods adopt a grey-world model for the white balance computation. An image gain is adjusted according to the pixel data of an image to make the mean of R/mean of G (the quotient of the mean value of primary color R intensities over the mean value of primary color G intensities) approximately equal to the mean of B/mean of G (the quotient of the mean value of primary color B intensities over the mean value of primary color G intensities) in an image. However, if the intensity of an external light source is weak, or the image includes a large number of monochromatic blocks, any noise and slight change of brightness may result in alternate enabling and disabling of the automatic white balance functions, and a decrease in stability of the brightness of the image.
In view of the foregoing drawbacks of the prior art, the inventor of the present invention based on years of experience in the related industry to conduct extensive researches and experiments, and finally developed an automatic white balance control system, an automatic white balance module, and a method thereof in accordance with the present invention to overcome the drawbacks of the prior art.